727 fun

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furrystump

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So I was in staging for qualifying and clicked it into drive and it made a whirring sound for a sec and started to move. Moved it back and forth drive to neutral a bunch trying to recreate the sounds and it worked fine. Did my burn out and staged the car. Loaded the converter as usual, light goes green and.........nothing! Back it up and drive it back to the pits. Works fine, drive it around and it makes a couple of thunks/crunchy sounds but continues to move. I can take a hint, throw it in the trailer. Pull it apart and there’s some debris in the pan, but not much. It is steel splinters.

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It’s got no end play and the output shaft won’t turn by hand. Pull the pump and both clutch packs. No issues. Both planetary’s spin freely on the bench and the pinions look good. Get to the low/reverse drum and it won’t spin or slide out.

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Notice that it is very slightly sitting higher on one side. Finally get it out and who would have guessed....

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Dug out my spare 727 case and will swap everything over. Glad I bought a blanket even though I didn’t use it. Putting a 16 element in it.
 
Actually me too, I thought planetary or sprag.
 
900+ runs on the sprag, put clutches/steels/bands seals in it 2 years ago. It looked fine when I refreshed it then.
 
It was the first run of the weekend. The week before, I believe this is it. Right side, it was funny I had wondered why the other car was just eating my lunch from 60’ out to 1000’ I have run against that car a million times and know it well, but he has made changes. Still I usually have 2-3 mph on him and should be pulling on him more after 330.

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If I’m next to him by 60’ I should have him dead to rites. I think it was either slowly slipping through the sprag or dragging through it.
 
It is in the plans, 10 years ago it started life as a street car with no intention of racing it. Then POOF! Like magic it’s a race car! Didn’t see it coming!!!! When the other fastback is ready for drivetrain the 727 will slide over to it and I will go 904. You need different convertor and driveshaft is different length.
 
The 904 is the way to go, just be sure to put the heavy duty sprag in it. I have one in the Demon & a spare, just in case. Both have RMVB & trans brake.
 
The 904 is the way to go, just be sure to put the heavy duty sprag in it. I have one in the Demon & a spare, just in case. Both have RMVB & trans brake.

Dont have to worry about drum explosions in a 904 so not sure why a beefier sprag would be needed
 
there is no heavy duty sprag for the 904.....the stock is riveted in and can be removed by drilling the heads off the rivets....have done it a couple of times....

just repaired one a couple of months ago.....
 
Yes it does have low band apply. Saved me some headaches.........or foot aches! Burn-out in first only so the low band helps out the sprag, for the last 9-10 years. Definitely got my monies worth out of it.
 
Dont have to worry about drum explosions in a 904 so not sure why a beefier sprag would be needed
It might not explode, but it can still tear up the sprag. Not sure the make a 16 or more element sprag for 904, but the car will eventually get a 904
 
It might not explode, but it can still tear up the sprag. Not sure the make a 16 or more element sprag for 904, but the car will eventually get a 904

True
Sprag can get torn up for lots of reasons. Case can get damaged when it rolls too.
Welcome to an automatic trans.
Big thing is it doesnt grenade like a 727, and is lighter and quicker.
Not gonna maybe lose a leg or worse, and damage your car
 
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